The cable assembly used for an electrosurgical pencil includes a cable and a attachment plug. Until now, all manufacturers of electrosurgical pencils have paid little attention to the cable assembly. They typically have purchased existing traditional general-use three-core cables with an existing attachment plug to equip their electrosurgical pencils.
As for the cable, a three-core cable for general-use must have three cores in the same conductor diameter and same insulation, while in an electrosurgical pencil, only one core is used for transmitting heavy power and the other two are only used for transmitting signals. Therefore, the conductor diameter and insulation of the other two cores can be greatly reduced. To do so, not only the cost can be reduced, but also the operational function of the cable can be raised. For example, the main core of said three cores can still meet the test according to AAMI standard. Therefore, the conductor diameter should be AWG#26 (or 7×0.16 mm strands) and the insulation thickness will be thicker. Since the other two cores are only used for transmitting signals, only AWG#28 (or 4×0.16 mm strands) will be enough. The general-use cable will be more expensive, rigid and heavy than the Safety Standard (AAMI) required. If the cable is made per the actual requirements, the cable will be thinner in outside diameter and cheaper in cost. Besides, it will be lighter in weight and more flexible than the traditional general-use cable. This may help to enhance the precision of a surgical operation.
As for the attachment plug of the cable for an electrosurgical pencil, since the traditional attachment plug is designed only per Safety Standard (AAMI), the practicality of the surgical operation was conventionally not considered. For example, in safety testing, each of three cores should be tested with strong current under high voltage, and testing focuses on the temperature-rise, insulation break-down, etc. In any power transmitting case, since the current is strong and the voltage is high, the contacting requirement is low. Even if the contact between the plug-pins and the socket is bad, there will be only an interruption of the current transferring and no safety problem will take place. By contrast in the electrosurgical pencil, since the two cores are transmitting signals, no strong current and high voltage are used; therefore, the contact between the plug-pins and socket must be more sensitive than in safety testing. If the contact between the plug and the socket is unstable and the signal transmitting is interrupted, though there is no safety problem to the device, there may be a terrible safety problem to the patient during the operation. Therefore, the traditional attachment plug is not ideal to use in different electrosurgical generators. For example, plug-pins used to transmit signals should be more sensitive than plug-pins used to transmit power supplies. Simply speaking, the attachment plug used for power transmitting can not meet the requirement of transmitting stable signals.
Furthermore, if the plug-pins are too loose to plug in, they will easily pull out during the operation. If they are too hard to plug in, they will be too difficult to use.